There are many characteristics of epics. Some of the main ones seen in Beowulf are:
- Feasts or Ceremonies between moments of exciting action
- Great battles
- Sea voyage
- Search or Quest for a life-giving item or to rid the land of a dangerous menace
- Good eventually wins over evil
- Evil's story is often told so we almost feel empathy or understand evil's point of view
- The last verse/canto relates the death of the wounded, elderly hero
Some of the secondary epic characteristics in Beowulf are:
- Diversions about the histories and naming of objects
- List of the ancestry of the main characters
Like other epics, Beowulf is long. It also depicts the heroic deeds of a figure who is human, but still larger than life. Beowulf, like many (but not all) of the classical epics, was not originally composed in written form, but rather passed down in oral form by bards, singers who committed the main points of the story to memory and sang it for small audiences. Like many other epics, notably the Iliad, Beowulf includes long descriptions of the major characters' family lines and histories. The events of the poem, like in many other epics, open in medias res, as Grendel is already ravaging the Danes when the story opens. And like other epics, Beowulf occupies a prominent place in the national lore of the people that produced it.
A fine and focused answer.
Im also adding a relevant nd possibly useful reading link below, which might be of some help in understanding better the 'oral tradition' of the epic and other matters mentioned abobe.